Does the mystery model generalize?

I recently found a simple statistic that distinguishes with near-perfect accuracy between states that voted for Clinton and states that voted for Sanders. It would be interesting to see whether it generalizes to the Republican primary, or to the 2012 general, though I doubt it will.

State

???

2016 Dem primary

2016 GOP Primary

2012 General

Mississippi

37.3%

Clinton

Trump

Romney

Louisiana

32.4%

Clinton

Trump

Romney

Georgia

31.4%

Clinton

Trump

Romney

Maryland

30.1%

Clinton

Trump

Obama

South Carolina

28.5%

Clinton

Trump

Romney

Alabama

26.4%

Clinton

Trump

Romney

North Carolina

21.6%

Clinton

Trump

Romney

Delaware

20.1%

Clinton

Trump

Obama

Virginia

19.9%

Clinton

Trump

Obama

Tennessee

16.8%

Clinton

Trump

Romney

Florida

15.9%

Clinton

Trump

Romney

Arkansas

15.8%

Clinton

Trump

Romney

New York

15.2%

Clinton

Trump

Obama

Illinois

14.9%

Clinton

Trump

Obama

New Jersey

14.5%

N/A

N/A

Obama

Michigan

14.2%

Sanders

Trump

Obama

Ohio

12.0%

Clinton

Kasich

Obama

Texas

11.9%

Clinton

Cruz

Romney

Missouri

11.5%

Clinton

Trump

Romney

Pennsylvania

10.8%

Clinton

Trump

Obama

Connecticut

10.3%

Clinton

Trump

Obama

Indiana

9.1%

Sanders

Trump

Romney

Nevada

9.0%

Clinton

Trump

Obama

Kentucky

8.2%

N/A

Trump

Romney

Massachusetts

8.1%

Clinton

Trump

Obama

Oklahoma

8.0%

Sanders

Cruz

Romney

Rhode Island

7.5%

Sanders

Trump

Obama

California

6.7%

N/A

N/A

Obama

Kansas

6.2%

Sanders

Cruz

Romney

Wisconsin

6.1%

Sanders

Cruz

Obama

Minnesota

4.6%

Sanders

Rubio

Obama

Nebraska

4.5%

Sanders

N/A

Romney

Colorado

4.3%

Sanders

Cruz

Obama

Alaska

4.3%

Sanders

Cruz

Romney

Arizona

4.2%

Clinton

Trump

Romney

Washington

3.7%

Sanders

N/A

Obama

West Virginia

3.6%

Sanders

N/A

Romney

Hawaii

3.1%

Sanders

Trump

Obama

New Mexico

3.0%

N/A

N/A

Obama

Iowa

2.7%

Clinton

Cruz

Obama

Oregon

2.0%

N/A

N/A

Obama

Wyoming

1.3%

Sanders

Cruz

Romney

Utah

1.3%

Sanders

Cruz

Romney

New Hampshire

1.2%

Sanders

Trump

Obama

South Dakota

1.1%

N/A

N/A

Romney

North Dakota

1.1%

N/A

N/A

Romney

Maine

1.0%

Sanders

Cruz

Obama

Idaho

1.0%

Sanders

Cruz

Romney

Vermont

0.9%

Sanders

Trump

Obama

Montana

0.7%

N/A

N/A

Romney

I’ve left out Nebraska and West Virginia from the GOP side, because those races had only one candidate.

The general election is clearly regional; our mystery statistic doesn’t appear to be relevant. The GOP primary is more interesting: the only states Trump lost above our 8.0% cutoff are Ohio (Kasich’s home state) and Texas (Cruz’s), but he won seven states below the cutoff: Rhode Island, Nebraska, Arizona, West Virginia, Hawaii, New Hampshire, and Vermont. Of these, Rhode Island, West Virginia, New Hampshire, and Vermont are East Coast states, and Trump has won every East Coast state except Maine; of the rest, Arizona is an exception for the Democrats as well, for obvious reasons that would be taken into account in a slightly more complex version of this model.

Another way to put this is: above our 8.0% cutoff, 10 Trump states voted for Obama in 2012 and 12 voted for Romney, but below it, every Trump state but Arizona went to Obama. (Below the cutoff, 6 non-Trump states went to Romney and 5 went to Obama.)

So: the mystery model appears to hold for the GOP primary, but there’s a regional effect on top of it.

Primaries are usually by county. I’m working on county-level Democratic primary analysis now, because I’d like to be able to call Kentucky. Kansas, Minnesota, and Alaska are by congressional district, so I’m ignoring them. On the Republican side, Wyoming is by groups of two counties, which is sensible: on the Democratic side, about half of the counties in Wyoming were won by a margin of zero or one.